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Tracking Antimicrobial Resistance Genes across Canada: Coast-to-Coast-to-Coast
PAUL GEORGE, Marc Veillette, Amélia Bélanger Cayouette, Mahsa Baghdadi, Maosheng Yao, Nathalie Turgeon, Jacques Corbeil, Caroline Duchaine, Université Laval
Abstract Number: 57
Working Group: Bioaerosols
Abstract
The spread of antimicrobial resistance genes throughout the environment is of great concern to public health and policymakers. Antibiotic-resistant bacteria can spread throughout the wider environment through the air in bioaerosols originating from anthropogenic sources, such as agriculture, wastewater treatment, or hospitals, and pass resistance genes to other bacteria via horizontal gene transfer. Resistance genes may differ depending on the source, so understanding the diversity of resistance genes in the environment is necessary to make actionable policy to combat their spread. Here, we apply a recently developed method using passenger vehicle air filters as passive monitors of airborne bacteria and antimicrobial resistance genes across Canada. We have collected 317 cabin pollen filters from individuals, city governments, and vehicle service departments from 27 locations in 9 provinces. Approximately 20 g of filter material was removed from each filter. The subsample was processed using a stomacher Mix 1 homogenizer in saline and 0.05% tween 20 solution to collect dust and bacteria. Large particles were removed with differential centrifugation and 3 mL aliquots were collected after high-speed centrifugation. We extracted DNA from these aliquots and quantified copy numbers of 16S and the ratio of resistance genes using qPCR. There is evidence of a widespread distribution of various tetracycline resistance genes, including tet32, tetlL, tetM, and tetW, which appear in large cities and smaller well-connected population centres across Canada. However, most tetracycline resistance genes were not detected in filters from remote locations. We also detected widespread sulphonamide resistance, namely sul1, in these samples. There is little evidence of aminoglycoside resistance genes and unclear trends in the colistin resistance gene mcr-1. We are working on expanding our resistance panel and identifying the sources of resistance genes is ongoing.